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[Diastolic dysfunction and its relation to myocardial fibrosis in essential hypertension]
N Sugihara1, A Genda, M Shimizu
1Second Department of Internal Medicine, School of Medicine, Kanazawa University.
Insights
Myocardial interstitial fibrosis correlates with diastolic dysfunction in hypertensive patients. Increased fibrosis and wall thickness are linked to impaired diastolic function, even in mild to moderate hypertension.
Area of Science:
- Cardiology
- Pathology
Context:
- Systemic hypertension (HT) can lead to diastolic left ventricular dysfunction.
- The role of myocardial interstitial fibrosis in this dysfunction requires further elucidation.
Purpose:
- To investigate the correlation between myocardial interstitial fibrosis and diastolic dysfunction in patients with mild to moderate systemic hypertension.
- To compare fibrosis levels and diastolic function parameters between normotensive subjects and hypertensive patients with and without left ventricular hypertrophy (LVH).
Summary:
- Hypertensive patients, with or without LVH, exhibited significantly greater myocardial fibrosis percentages compared to normotensive controls.
- Diastolic dysfunction, indicated by prolonged isovolumic relaxation time (IRT) and reduced rapid filling volume (RFV) and its quotients, was observed in hypertensive groups.
- Multiple regression analysis revealed significant correlations between wall thickness, fibrosis percentages, and diastolic parameters (IRT, RFV, RFV/EDV, RFV/SV).
Impact:
- Findings suggest that myocardial interstitial fibrosis is a significant correlate of diastolic dysfunction in systemic hypertension.
- This highlights fibrosis as a potential therapeutic target for managing diastolic dysfunction in hypertensive individuals.
- The study provides quantitative correlations, aiding in risk stratification and understanding disease progression.
Abstract:
This study elucidated diastolic left ventricular dysfunction and whether myocardial interstitial fibrosis correlates with diastolic dysfunction in mild to moderate systemic hypertension (HT). Six normotensive subjects, 18 hypertensive patients without left ventricular hypertrophy (LVH) and 10 hypertensive patients with significant LVH were evaluated. M-mode echocardiography was used to determine fractional shortening (FS), isovolumic relaxation time (IRT), and left ventricular filling volume during rapid and slow filling periods and the atrial contraction period (RFV, SFV, ACV). The quotients of the left ventricular filling volume and the end-diastolic volume and stroke volume were also calculated. Simultaneous biventriculography was used to determine the end-diastolic thickness of the interventricular septum and posterior wall. Right ventricular endomyocardial biopsies were performed to calculate the percentages of fibrosis. The FS was normal in all groups. The percentages of fibrosis in the two HT groups were significantly greater than those in the normals. The IRT of the HT groups was significantly greater, and the RFV, RFV/EDV and RFV/SV were significantly less than those of the normals. Multiple regression analysis showed that the wall thickness and the percentages of fibrosis correlated significantly with IRT, RFV, RFV/EDV and RFV/SV. The standard coefficients of correlation of wall thickness and the percentages of fibrosis were 0.333 and 0.239 in respect to IRT, and -0.304 and -0.473 in respect to RFV. There were significant correlations between the percentages of fibrosis and RFV (r = -0.675), RFV/EDV (r = -0.664) and RFV/SV (r = -0.602) in the normals and in cases of HT without LVH.(ABSTRACT TRUNCATED AT 250 WORDS)